This invention relates to a valve assembly generally and, in particular, to a unitary injection moulded plastic one-way valve for fluid dispensers, particularly but not exclusively soap dispensers, and replaceable fluid dispensing units and/or fluid dispensers incorporating the same.
Automated dispensers for soap and other fluids are known as, for example, illustrated in U.S. Pat. No. 5,836,482 to Ophardt et al issued Nov. 17, 1998 and U.S. Pat. No. 5,960,991 to Ophardt issued Oct. 5, 1999, the disclosures of which are incorporated herein by reference. These dispensers use as a unit a container for a fluid to be dispensed and a pump for dispensing the fluid therefrom. The unit is removable and disposable. In order to prevent dripping of the fluid through the pump, it is known to provide anti-dripping mechanisms such as a one-way valve with the unit, and one such one-way valve is as illustrated in FIG. 2 of said U.S. Pat. No. 5,836,482. The valve configuration as taught therein involves a number of parts and also suffers the disadvantage of requiring complex arrangements for the dispenser. Since dispensers of this type are normally battery operated, it is advantageous that the configuration of the valves that may be employed for the purpose should desirably be such that the frictional forces arising in the fluid flow which are required to be overcome by the pump are minimal so as to increase the useful life of the batteries and, therefore, to minimize the size and quantity of batteries required. Moreover, as the unit with the valve is disposed after use, it is also advantageous to have a valve which is recyclable, as well as inexpensive.
It is an object of the present invention to at least partly overcome the abovementioned disadvantages.
Another object of this invention is to provide a valve assembly of an improved configuration.
A still another object of this invention is to provide a unitary valve for use in a fluid dispensing unit such as a soap dispensing unit and/or dispenser.
A further object of this invention is to provide a unitary valve which can be made by injection molding from recyclable plastic materials.
A still further object of this invention is to provide a cost effective and energy efficient valve assembly for use in removable, replaceable fluid dispensing units, such as soap dispensing units, and fluid dispensing units and/or dispensers incorporating the same.
With these and other objects in view the present invention provides an improved valve assembly, particularly a unitary injection moulded plastic one-way valve for controlled dispensing of a fluid from a fluid dispensing unit, such as a soap dispensing unit. The unit may incorporate a fluid dispensing pump, preferably a rotary pump. The valve may be located downstream from the pump and preferably inside the delivery tube thereof. Preferably, the valve comprises an integral valve member adapted to be removably received and secured within the delivery tube of the pump. The valve member may comprise a sealing member, a support member and a securement member, and it is formed entirely from a plastic material as a single piece by injection molding. The sealing member is at one end of the support member and the securement member is at the other end thereof The valve member is resilient or adapted to be resilient, and the resiliency may preferably be with the support member and/or the sealing member. The valve member is preferably located within the delivery tube by securing the securement member at the outlet of the delivery tube. When so secured, the sealing member preferably biased by the support member engages and seals the inlet port of the delivery tube and prevents fluid flow therethrough, and, however, fluid can flow down therethrough if there is a pressure differential across the sealing member sufficient to deflect the sealing member away from sealing engagement with the inlet port. The resiliency of the valve member is so adapted that it is sensitive enough to a pressure differential that may be created by the pump, and the sealing member resiliently deflects away from sealing engagement thereby opening the inlet port and permitting fluid flow therethrough.
In a preferred embodiment, the inlet port of the pump delivery tube may be provided with an annular shoulder directed towards the outlet thereof, and the delivery tube and its inlet port, annular shoulder and outlet are generally circular in cross section about a common longitudinal axis
The function of the sealing member is to open and close the inlet port of the delivery tube, and it may have any shape provided it serves this function. Preferably, its outer periphery configuration may match with the inner periphery configuration of the inlet port so as to achieve proper fluid sealing. The sealing member may preferably comprise a circular sealing disc with a radius larger than a radius of the inlet port. The sealing disc may have a circular central portion with an annular peripheral flange portion extending radially outwardly about the central portion. The support member may be connected to the central portion of the sealing disc. Alternatively, the sealing disc may have a convex outer surface appearing like a mushroom-top. The annular flange portion of the sealing disc may preferably be resilient and adapted to be resiliently deflected away from sealing engagement with the inlet port towards the outlet. Preferably, the outer periphery of the sealing member may be provided with an axially extending guide member adapted to pass freely through the inlet port and locate and guide the sealing member.
According to another embodiment, the securement member may comprise a circular disc adapted to be removably secured to the outlet of the delivery tube, and this disc may be provided with a passageway centrally therethrough for exit of fluid. The support member may be connected to the disc at a suitable location radially outwardly of the passageway. Preferably, the outer wall of the disc is provided with a circumferential slot matching with and adapted to receive an inwardly extending circumferential ridge at the outlet of the delivery tube in a friction fit relation. The central passageway opens preferably to an outwardly extending exit tube integrally formed at the outer periphery of the disc.
Preferably, the entire or a portion of the support member is resilient or adapted to be resilient, and when it is subjected to compression urging its ends together along a longitudinal central axis of the valve member it resiliently deflects with its ends biasing away from each other. Preferably, the support member may comprise a pair of leg members with each leg member comprising a mirror image of the other disposed symmetrically about the longitudinal central axis thereof. The two legs may be spaced apart and the spacing therebetween may vary from one end to the other. The distance between the two legs may be maximum at their middle portion and it may gradually decrease with increasing proximity to their ends. According to a preferred embodiment, the two leg members are V-shaped and inwardly opening with their bent portion located around intermediate the sealing member and the securement member at their ends.
The valve member when secured in the delivery tube being in a compressed state exerts a pressure sufficient to seal the inlet port of the delivery tube when the pump is idle but not exceeding the pressure differential created by the pump in the opposite direction so that the inlet port opens and lets the fluid to pass there through when the pump is in operation.
Accordingly, in one aspect of the present invention, there is provided a valve assembly comprising:
a delivery tube having an inlet port at an inlet end and an outlet at an outlet end,
an annular shoulder about the inlet port at the inlet end directed towards the outlet,
a valve member comprising a sealing member, a support member and a securement member,
the support member having an inner end and an outer end,
the support member carrying the sealing member at the inner end and the securement member at the outer end,
the valve member removably received in the delivery tube by the securement member being removably secured in the outlet with the sealing member biased by the support member into sealing engagement with the annular shoulder about the inlet port to seal the inlet port to fluid flow therethrough other than fluid flow under a pressure differential across the sealing member sufficient to deflect the sealing member towards the outlet away from sealing engagement with the annular shoulder, and
the valve member being formed entirely from a plastic material as an integral member by injection molding.
According to another aspect of the present invention, there is provided a valve assembly comprising:
a chamber and a resilient valve member secured therein,
the chamber having an inlet port at inlet end and an outlet at outlet end thereof,
the valve member being formed entirely from a plastic material as an integral member by injection molding and comprising a sealing member at one end, a securement member at the other end and a support member connecting the two,
the securing member being secured in the outlet with the sealing member biased by the support member being in a fluid seal engagement with the inlet port, and
said sealing engagement being resiliently deflectable under a pressure differential across the sealing member.
According to a further aspect of the present invention there is provided a device for dispensing a fluid comprising:
a housing,
a removable, replaceable fluid dispensing unit removably mounted to the housing,
means for activating and controlling the dispensing unit to dispense fluid there from,
the dispensing unit comprising:
a container for the fluid to be dispensed and communicating with a pump activable and controllable by the activating and controlling means, and
a valve assembly provided downstream from the pump,
wherein:
the valve assembly comprises a resilient valve member secured within a delivery tube of the pump,
the delivery tube having an inlet port at inlet end and an outlet at outlet end thereof,
the valve member being formed entirely from a plastic material as an integral member by injection molding and comprising a sealing member at one end, a securement member at the other end and a support member connecting the two,
the securing member being secured in the outlet with the sealing member biased by the support member being in a fluid seal engagement with the inlet port, and
said sealing engagement being resiliently deflectable under a pressure differential across the sealing member generated by the pump.